Individual identification of yellow-eyed penguins / hoiho

Yellow-eyed penguins / hoiho do not have any natural markings that allow researchers and conservation managers to tell individuals apart. Instead birds are “marked” with transponders to help us recognise individuals.

Transponders

The Trust now uses transponders to mark hoiho at all of our reserves.

A transponder is a tiny microchip embedded in glass (similar to those used to identify your dog). The microchip is inserted under the skin at the back of the neck by a trained operator using a needle.

Each time a penguin is sighted, a transponder wand reader is waved over the back of the bird to obtain the unique 15 digit code.

Transponders allow long-term data information to be gathered about the birds.

Identification is crucial to the management of hoiho. This information can be used to answer questions such as how many birds there are in the population, and what their survival and productive rates are.

Flipper bands

Lance Richdale began marking hoiho in 1936 using leg rings. In 1973 Alan Wright (NZ Wildlife Service) used the first flipper band at Penguin Beach, Otago Peninsula.

Using banded birds, Richdale established much of the basic population biology and behaviour knowledge of the species. A valuable research programme which continues to band birds has existed at Boulder Beach, Otago Peninsula for more than 30 years.

In the past, the Trust marked penguins with flipper bands on its reserves. The bands have now been suspected of causing injury through abrasion and entanglement, and of affecting foraging performance in other penguin species. Bands also require ongoing checks and maintenance. Debate on the impact of flipper banding continues in the scientific literature and led the Trust to favour transponders.